1. Field of the Invention
The present disclosure relates to current measuring apparatuses, image forming apparatuses, conveyance apparatuses and methods for measuring current.
2. Description of the Related Art
Conventionally, an amplifier for amplifying an input signal, such as an operational amplifier, is known.
Also, the following method is known. That is, in a combination of a first operational amplifier and a second operational amplifier, a feedback resister is coupled to a feedback section of the first operational amplifier while an input resistor is coupled to an inverted input terminal of the first operational amplifier. Also, a non-inverted input terminal of the second operational amplifier is grounded while an output terminal of the second operational amplifier is coupled to the input resistor. It is known that an input offset can be prevented from being amplified according to a gain without detecting the input offset by using the non-inverted amplifier circuit as described above (for example, Patent Document 1, etc.).
However, in the conventional technology, two operational amplifiers are required in order to measure current. Therefore, in the conventional technology, cost for measuring the current flowing in a motor may be increased.